This program project grant has supported an integrated multidisciplinary program in environmental carcinogenesis relating retrospective case-control epidemiological studies and experimental research. The latter includes cell culture, animal model, and human subject investigations. Proposed studies by organizational division in the forthcoming period are: 1) Epidemiology: various cancer studies in the U.S. and overseas, emphasizing GI tract and breast cancer. 2) Nutrition: endocrine-related cancer studies via hormonal effects of high-fat diets in various human populations; also dietary studies on colon carcinogenesis utilizing fecal analyses. 3) Molecular Biology and Pharmacology: study of the mechanism of the high-fat effect on breast cancer development using animal models and cell cultures; also the mechanism by which alcohol may act as a cocarcinogen in oral cavity cancer. 4) Experimental Pathology: model systems for the study of the pathogenesis of tumor development. 5) Experimental Carcinogenesis: investigation of the carcinogenic action of hydrazines, nitrosamines, and methylated polynuclear hydrocarbons, in addition to bracken fern. 6) Occupational Health and Toxicology: assessment of cancer risk to welders as a model population.